Electromagnetic thread-tension control assembly



Nov. 7, 1967 A, FR 3,351,296

ELECTROMAGNETIC THREAD-TENSION CONTROL ASSEMBLY Filed June 24, 1966 30 22 28 I IZZ FIG.3. FIG.4.

INVENTOR Karl Anton Fre'i BY I AT ORNEY United States Patent 3,351,296 ELECTROMAGNETIC THREAD-TENSION CONTROL ASSEMBLY Karl Anton Frei, ()nstmettingen, near Balingen, Germany, assignor to Gebruder Frei, Onstmettingen, Germany, a

corporation of Germany Filed June 24, 1966, Ser. No. 560,265 9 Claims. (Cl. 242-45) This invention relates generally to an improved threadtension control assembly, particularly adapted for use in the textile industry or the like, and more particularly to an improved electromagnetic thread-tension control assembly which will effectively atford a plurality of parameters of controland facilitate the control of tension on a plurality of threads which are being simultaneously drawn through winding apparatus or the like.

Various types of thread-tension controls have been used in the past in the prior art, the major portion of such controls utilizing a spring tension. The springs used in such devices are subject to fatigue after constant usage over an extended length of time, generally require continual adjustment in order to accomplish the function for which they are designed, and matching of the springs is generally complicated and time-consuming.

A primary object of the present invention is to provide an improved electromagnetic thread-tension control as sembly in which means are provided for controlling the current flow to an electromagnetic means for effectively imposing a magnetic field on a rotatable armature means subject to torque imposed by a continuous length of thread subjected to a predetermined tension.

Another object of the present invention is to provide an electromagnetic thread-tension control assembly in which the effective magnetic lines of force embodied on a rotationally mounted armature may be controlled by adjusting the effective gap between armature poles and pole elements of the electromagnetnc means.

A still further object of the present invention is to provide in an electromagnetic thread-tension control assembly including an electromagnetic means and armature means journaled in the effective field thereof, counterbalance means on said armature means for imposing a predetermined resistance to the torque when applied on the armature means by a continuous tensioned thread normally subjecting the armature means to a predetermined torque.

These, together with other objects and advantages of the invention will become apparent from consideration of the following specification when taken in conjunction with the drawing forming a part thereof, in which:

FIG. 1 is an elevational view of one embodiment of the novel electromagnetic thread-tension control assembly, showing in phantom lines an alternate position of the armature of the assembly, and showing diagramatically a typical control circuit for the assembly;

FIG. 2 is a side elevational view looking from left to right at FIG. 1, and showing by means of phantom lines a control switch for controlling a power circuit (not shown);

FIG. 3 is an elevational view of another embodiment of the novel electromagnetic thread-tension control assembly and showing in phantom lines an alternate position of the armature, and showing diagramat-ically an electrical circuit such as that shown in FIG. 1; and

FIG. 4 is a side elevational view, similar to FIG. 2, and looking from left to right at FIG. 3.

Referring to the drawing in detail and first considering FIGS. 1 and 2, an electromagnetic thread-tension control assembly is indicated generally at and comprises a base means or member indicated generall at 12 having thereon an electromagnetic means indicated gener- 3,351,296 Patented Nov. 7, I967 ally at 14 and having journaled thereon armature means indicated generally at 16.

The base member 12 is produced from a material which is a non-conductor of electricity and will have suitably secured thereon connectors or contacts 18 and 20 to which will be operatively connected a circuit indicated generally at 22. The circuit 22 includes a suitable source of direct current 24 operatively connected by conductors 26 and 28 by a rheostat control '30 (of any suitable character) which is operatively connected by conductors 34 to the contacts 18 and 20, respectively.

Although not shown, the contacts 18 and 20 are operatively connected to the windings or field coil of the electromagnetic means 14 in any suitable manner. The elec tromagnetic means 14 includes a pair of spaced, laterally projecting pole elements 36 and 38 respectively identified as N and S, as is conventional. The electromagnetic means 14 includes a central field coil 40, as is conventional in the art. Journaled axially to the coil 40 for rotation between the pole elements 36 and 38 is the armature means 16 which comprises an elongated bar element 42 having terminal end portions which would be magnetically attracted to the respective pole elements as shown, for example, by solid lines in FIG. 1 and respectively indicated as N and S.

Suitably secured to an armature hub 44 of the armature means 16 and extending diametrically and substantially at right angles to the terminal ends of the bar element 42 is a lever 46. Draped over one end portion of the lever 46 is a fragmentary portion of the continuous thread T which will be drawn therealong and be subject to a predetermined tension as is conventional in the textile industry on a spool winding machine, for example.

Suitable means is provided on the other end portion 50 of the lever 46 for imposing a counter-torque weight, necessitating a certain torque to be applied on the lever 46 by the thread T before the armature means rotates. The latter mentioned means comprises a knurled nut 52 which is threadedly engaged on the thread port-ion 54 on end portion 50 of the lever and is adjustable radially with respect to the axis of rotation of the armature means.

Projecting from the hub 44 of the armature in spaced relation from the axis of rotation thereof is an abutment element 56 which, when moved, has a path of travel engagable with a switch or contact element 58; see FIG. 2, of a control switch 60 suitably connected to conductors 62 and 64 of a control circuit (not shown) for controlling "a power source controlling drawing the continuous thread over the lever 46 at a predetermined speed and/ or tension.

Operation It will beclearly apparent to those skilled in the art that the rheostat 30 can be used to control a predetermined amount of current directed to the coil 40, and the ,coil 40 can be utilized to develop a magnetic field imposing a predetermined amount of resistance to rotation on the armature means 16. Accordingly, this provides one parameter of control for the electromagnetic thread-tension control assembly. The nut element, by virtue of its adjusted position radially with respect to the axis of rotation of the armature element, will likewise produce a predetermined amount of resistance to rotation of the armature when the lever portion 48 is subjected to torque due to the thread T being continually drawn thereover.

When knots, snags, etc. develop in the thread T, and tension on the thread (and imposed on lever 46) exceeds that for which the assembly is adjusted, the lever 46 and armature will move toward the phantom line position clockwise as shown by FIG. 1, thus overcoming the magnetic field developed by the coil 40 (which tends to prevent rotation) and the resistance to rotation im- 3 posed on the armature means by the adjustable counterbalance weight 52.

As the hub 44 rotates, the abutment element 56 will disengage the switch element 58 of the control switch 60 to etfectively control suitable means (not shown) functioning to continuously draw the thread T in a winding apparatus, for example.

Referring to FIGS. 3 and 4, another embodiment of the electromagnetic thread-tension control assembly is disclosed and is indicated generally at 100. The assembly 100 includes a base means or member 112 having mounted thereon electromagnetic means indicated generally at 114 and armature means indicated generally at 116; this is essentially the same arrangement as in FIGS. 1 and 2.

The base member 112 includes a base element produced from a suitable electrical non-conductor and has contacts 118 and 120 operatively connected to a control circuit 122 similar to that described in the previously described embodiment.

Mounted on the base member 112 in any suitable manner, and similar in all major respects to the electromagnetic means 14 of the previously described embodiment, is a coil 140 operatively connected to laterally extending, spaced pole elements 136 and 138. It will be observed that the current flowing to the coil 140 may be controlled through the adjustment of the rheostat 130 of the circuit 122 to accordingly control the magnetic field of the electromagnetic means. Journaled between the pole elements 136 and 138 in any suitable manner, axially of the coil 140, is an elongated bar element of magnetic material having terminal end portions 143 and 145 which project in their path of travel and will engage the pole elements 136 and 138, respectively, i.e., if the armature means 116 is rotated in a counter-clockwise direction; see FIG. 3.

The armature means 116 has extending diametrically, with respect to the axis of rotation thereof, a lever 146 having draped over portion 148 thereof a continuous and tensioned thread T as in the previously described embodiment. Likewise, the end portion 150 of the lever 146 has adjust-ably threaded thereon a nut or counterbalance element 152 which functions as in the previously described embodiment.

Still further, the hub 144 of the armature means has disposed thereon, in laterally spaced relation from the axis of rotation of the armature means, an abutment element 156 functioning with a switch element 158 of a control switch 160 similar to that mentioned with respect to the previously described embodiment.

One of the pole elements of the electromagnetic means 114, i.e., pole element 138, has extending transversely and therethrough an internally threaded bore portion 155 in which is adjustably mounted a machine screw 157, preferably of a non-conducting material. The terminal end portion 159 of the screw 157 will abutingly engage the adjacent end portion 145 of the armature means 116 to accordingly adjust the normal gaps 161 and 163 between the pole elements 136 and 138 and terminal end portions 143 and 145 of the armature means. This in efiect will control the efiective magnetic attraction of the poles 136 and 138 with respect to the armature.

Operation As in the previously described embodiment, the embodiment of FIGS. 3 and 4 incorporates the adjustable parameters of control, i.e., the amount of current directed to the electromagnetic means 114, and the resistance to torque via the adjustment of the counterbalance weight 152.

Additionally, the machine screw 157 may be adjusted to control the eiiective gaps 161 and 163 whereby the relative spacing of the poles of the armature and pole elements of the electromagnetic means may be preset,

4 thus providing means for controlling the initial effective resistance to rotation of the armature means.

It will be appreciated by those skilled in the art that a plurality or banks of electromagnetic thread-tension control assemblies 10 or may be utilized on a winding apparatus which would have a plurality of the threads T subject to substantially the same tension. Through the expedient of a central control manifold (not shown), all of the electromagnetic thread-tension control assemblies of the bank of assemblies could be instantly monitored by a single operator. Additionally, once the amount of tension to be imposed on a plurality of threads has been determined and the amount of current to be directed to the electromagnetic means has been determined, and the relative portion of the counterbalance weights has been determined and/ or the effective gap between is adjusted, relatively little, if any, subsequent adjustment is required.

Additionally, when the thread T is subject to a tension above that for which the apparatus has been previously adjusted, rotation of the armatures to the phantom line positions shown in either FIG. 1 or 3 would be effective to operate a control circuit to the power means for a thread winding apparatus or the like.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawing and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. A thread-tension control assembly for use on textile machines in which a predetermined tension is to be maintained on a continuously drawn thread or the like, comprising:

base means;

electromagnetic means on said base member for creating a magnetic field,

said electromagnetic means including spaced pole elements; and a magnetically-attractive armature means journaled for rotation on said base member between said spaced pole elements and having end portions normally attracted to said pole elements when said electromagnetic means is energized;

said armature means including a radially projecting lever for receiving a tensioned thread thereon whereby excessive tension on said thread over a predetermined value will cause said ar-mature means to rotate in one direction relative to said pole elements.

2. The structure as claimed in claim 1 in which said armature means includes a control element thereon for controlling a circuit.

3. The structure as claimed in claim 1 including means for controlling the effective magnetic field to which said armature means is subjected.

4. The structure as claimed in claim 3 in which said means for controlling the effective magnetic field comprises a rheostat control operatively connected to said electromagnetic means for adjustably-controlling the current flow to said electromagnetic means.

5. The structure as claimed in claim 3 in which said means for controlling the effective magnetic field comprises an abutment element adjustably mounted on a portion of said armature means and abutingly engageable with one of said pole elements whereby the effective gap between the armature means and said pole elements can be preset.

6. The structure as claimed in claim 5 in which said armature means comprises an elongated element projecting diametrically with respect to the axis of rotation of said armature means, said pole elements projecting in opposed spaced relation in the path of travel of opposite side portions of said elongated element.

7. The structure as claimed in claim 1 in which said pole elements project in spaced, diametrically opposed relation at opposite sides of the axis of rotation of said armature means and beyond the path of rotation of said armature means.

8. The structure as claimed in claim 1 in which said lever extends diametrically with respect to the axis of rotation of said armature means, one end portion of said lever means having a portion for receiving said tensioned thread thereover, the other end portion of said lever means including a counterbalance element for resisting the effective torque required to rotate said armature.

References Cited UNITED STATES PATENTS Buden 242-154 Lemarchand 242-150 Hermanns 242154 Bejach 24275.51 X

STANLEY N. GILREATH, Primary Examiner. 

1. A THREAD-TENSION CONTROL ASSEMBLY FOR USE ON TEXTILE MACHINES IN WHICH A PREDETERMINED TENSION IS TO BE MAINTAINED ON A CONTINUOUSLY DRAWN THREAD OR THE LIKE, COMPRISING: BASE MEANS; ELECTROMAGNETIC MEANS ON SAID BASE MEMBER FOR CREATING A MAGNETIC FIELD, SAID ELECTROMAGNETIC MEANS INCLUDING SPACED POLE ELEMENTS; AND A MAGNETICALLY-ATTRACTIVE ARMATURE MEANS JOURNALED FOR ROTATION ON SAID BASE MEMBER BETWEEN SAID SPACED POLE ELEMENTS AND HAVING END PORTIONS NORMALLY ATTRACTED TO SAID POLE ELEMENTS WHEN SAID ELECTROMAGNETIC MEANS IS ENERGIZED; SAID ARMATURE MEANS INCLUDING A RADIALLY PROJECTING LEVER FOR RECEIVING A TENSIONED THREAD THEREON WHEREBY EXCESSIVE TENSION ON SAID THREAD OVER A PREDETERMINED VALUE WILL CAUSE SAID ARMATURE MEANS TO ROTATE IN ONE DIRECTION RELATIVE TO SAID POLE ELEMENTS. 